| 摘要 |
PURPOSE: A protection element of a semiconductor device is provided to increase a holding voltage by inserting a blocking MOSFET(metal-oxide-semiconductor field-effect transistor) having a floating gate into the well of a low voltage-triggered SCR(semiconductor controlled rectifier), and to reduce a trigger voltage by easily inserting a current source capable of increasing a substrate voltage. CONSTITUTION: A semiconductor substrate(1) is prepared. The first region of the second conductivity type is formed in the substrate. The second region of the first conductivity type is connected to the first terminal(41) to be connected to the outside, formed in the first region. The third region of the second conductivity type with a density higher than the first region is formed in the first region, contacting the second region and connected to the first terminal. The fourth region of the second conductivity type is formed in the substrate, separated from the first region and having a density higher than the first region. The fifth region of the second conductivity type is formed in the interface between the substrate and the first region, having a density higher than the first region. The sixth region of the first conductivity type is formed in the first region, contacting the fifth region. The first gate structure is formed on the substrate between the fourth and fifth regions, connected to the second terminal(42) to be connected to the outside. The second gate structure of a floating structure is formed on the substrate between the sixth and second regions. |
